Gauge



J. AA. GREEN.

GAUGE. APPLICATION FILED AUG-I7, |921.

Patented Oct. 24, 1922.

Patented @ch 24:, i922.,

hitter@ JosnrnT A. ennnn, or rnovrnnnon, Rnonn rstann, fissrenon To rnnnnz-in rnonuofrs consort-.firten or Pnovi'onncn, iai-remi istanti, a coaronn'rion l GAUGE.

Application filed August 1'?, 1921. Serial No. 492,890.

To all 'whom t may concern.'

Be it known that l, Josnrri MAGREEN, a citizen of the United States, and resident of Providence, county of Providence, and State of Rhode island, have'invented an improvement in Granges, of which the following. description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings representing like parts.

My present invention relates to gauges, and more particularly to indicating gauges for measuring or indicating the amount of variation of av surface from a true plane, the amount of variation of 'a cylinder from a true cylinder, the amount a true plane or cylindrical surface varies from any desired pla-ne, or the like.

' Vln'machine vvorlr, such for example, that performed in 4a lathe, planer, milling machine, grinder, or the like, a great deal of time lis consumed in truing-up piece 'of Work preparatory to `performing `the machining operations thereon. ldor example, it is frequently necessary to clamp a cylinder in position on the face plate of a lathe or grinding machine preparatory yto performing the"` finishing grinding operation thereon. It is Well known that such settingup operation must be accurately performed, and frequently requires considerable time. Various instruments have been designed to assist the operative Ain ascertaining the amount of error in the setting of the Work, in order that the same be corrected with certainty and quickness. -Such prior instruments, hovvever, as far as l am aware, are not entirely satisfactory, either because of their crudeness, and hence their inaccuracy, or because of their complexity and expensive construction. It has been customary in such instruments to form the segment and rod gears as a partial gear connection only, and this arrangement involving considerable Wear, would eventually become loose vand inaccurate through Wearing. in my present invention it is an important feature to obviate this diiliculty and to form one of the gear members which transmits the movement from the Workto the indicating dial With means to compensate for Wear. ln the particular gauge construction as herein shown, l prefer to form :the rod vvithvperipheral threads or teeth running entirely around the the rod as a complete Worm or gear, and then to provide the rod and the tubular casing therefor with a plurality of keyiva-ys or the like permitting different radial positions. rThis permits me to shift the gears when Worn to a new place, and thus compensate for Wear and thereby to maintain the gauge in its positive accuracy and for a relatively long life of usefulness,

l have overcome the object-ions above pointed out, and to this end have designed the indicator forming the subject-matter of the present invention. ln my improved device, l arrange anv indicating needle or hand, voperated through gearing controlled bythe Work to be measured, and the movement ofl this needle or hand may be multiplied to any desired extent, over the movementl of the gearing; that is, the movement of the indicating needle or hand may be once, tvvice, thrice, or any desired times as great as the amount of error in the setting-up ofthe ivorl ln indicating instruments, such as gauges, the indicating mechanism is ordinarily built into the gauge, and is not only insensitive, but also expensive to manufacture. easy to get out of order, and requires great skill to assemble, To remedy this defect of prior instruments, I manufacture my improved indicating mechanism as a unit, to he afterwards )laced in the gauge, and am thus enabled to economically manufacture the same, and to easily and accurately adjust the mechanism and then assemble it inthe gauge.

The principal objectof my invention, therefore, is an improved indicator or gauge.

Another object is an improved siuface gauge that is accurate, easy to adjust and assemble, and the indications of which are quickiy and easily read or interpreted.

Still another object is an improved unit indicating mechanism for gauges and the like, havingadjustable means to compensate for ivear, thus insuring long usefulness with precision.

Other objects and novel features of the construction and arrangement of parts comprising my improved device vvill appear from the following description. Y

In the accompanying ydrawings illustrating the preferred'embodiment of my invention,

Fi l is a front elevation;

Fig. 2Ais a side elevation; 110

Fig. is a section on the line 3-8 of Fig. 1;

Fig. l is a plan showing the method ot attaching the bezel ring to the'case; and

Fig. 5 is a section on the liiie 5-5 ot Fig. 1. y

Referring to the drawings, designates the indicator case and 11 a tubular barrel termed integral therewith, or connected thereto in any suitable manner. The lower end oit the barrel 11 is provided, on the interio with a plurality of circuin:terentially arranged keyways 12in which slide a plurality ot keys 13, iiormed integral with or attached to the indicating rod 14;. The upper end of the indicating rod 1a is reduced in diaineteiI at 15 and is a sliding lit in a tension adjusting screw 16, which screws into the upper threaded end ot the barrel 11. Ou the reduced end 15 is secured a collar 17, while between the lower end olf the adjusting screw 16 and the collar 17 is a coil spring 18, the function oi which will be hereinafter described.

Secured in the case 10 by bolts 19 is an indicating mechanism or movement comprising essentially a base plate 2O and a bearing plate 21, spaced apart from and secured to each other by posts 22. Rotatably mounted in thev base plate 2O and bearing plate 21 is a staff 23 to which is secured a seginental gear plate 24, at one end ot which are .arranged teeth 25 meshing with acircular rack 26 cut on the indicating rod 14 below the collar 17 while at the other end of the plate 2-/1 are arranged teeth 37 meshing with a pinion 27 attached to a staff 28 mounted, one end in the base plate 2O and the other end in a bearing plate 29 riveted or otherwise secured to the plate 20. A hair spring 30, attached one end to 'the staff 28 and the other end to a pin 31 on thebase plate 2O tends to move the stati 28, segmental gear plate 2li, and therefore the indicating rod 111, back to normal position. ri`he outer or free end of the staii 28 extends through a central opening in a dial plate 32, provided wit-h 'graduations 33 ot any desired character. This dial plate 32 is secured ina knurled bezel ring 34' by means ot a. corrugated tension spring 35. The bezel ring is provided witha crystal 36 to excludedirt, dust, or the like from the interior oit the case 10 and is secured to the case by ak plurality of screws 17.

A holder 38, which may be threaded, as shown at 39, or plain and ot any desired size and shape, is secured tothe tubular barrel 1.1, and is utilized to hold the -device in position for operation.

The keys 13v and keyways 12 make it impossible to rotate the rod 111,whiley at the same time allowing said rod to have a sliding movement in the barrel 11. The tensionv adgusting screw 16 is used to adjust the tension o1 the spring 18, this tension being sufri- Lasso/'e oi the gear teeth 26 into engagement with the segmental teeth 25. Thus, in case the instrument has become inaccurate through wearing of the engaging portions of the teeth 25 and rack 26, the thumb nut 16 is loosened, the rod 1e withdrawn suiiiciently tov free the keys 1,3 from their engaging keyways,` the rod 1db'eing then turned suiiciently to re-engage'the keyways at another point, thus bringing new and unworn portion oi the rack 26 into working engagement with the segmental gear 25. This simple adjustment thus automatically corrects, trues upland reveriiies the instrument, rendering it again as accurate as originally made.

The operation oit the device is as follows,

i it being assumed that it is desired to set up a cylinder-in a lathe preparatory to grinding the interior oi such cylinder to the de! sired size. The cylinder is strapped onto the tace plate of the lathe. (not shown), the improved gauge fastened to the tool post ot the lathe, and the freeend of the rod 14 brought into engagement with the interior ot the cylinder, as such cylinder is rotated. Should the cylinderV not be properlycentered, the rod 14 will engage the cylinder at but a single point and the amount such cylinder, is out of centre will be visually ndicated on the dial plate 32 by the needle or hand a0. Because of the multiplying'action of the operating mechanism of the gauge, the slightest variation of the work from its central position willV be readily apparent. By swinging 'the gauge in the tool post, so as to bring tliegtree end of the rod 14 into engagement with the bottom face of the cylinder, the distance of such face fromv a vertical plane located perpendicular to the arbor of the lathe will be visually indicated on the dial plate.

The above illustrates but one of the many uses to whichthe present invention may be applied, and other uses for the same will readily suggest themselves to those skilled in the art. Further, while l have shown and described the preferred embodiment of my invention somewhat in detail, it is to be understood that I may vary the size, shape land arrangement or' parts comprising my device within wide limits without departing from the spirit of the invention.

Having thus described my invention, what I claim as new, is;

1. An improved indicating unit Jfor measuring and indicating instruments, comprisinga base, a bearing plate attached thereto and spaced apart therefrom, a stati rotatably mounted in said base and plate, a hand and a pinion attached to the stal, a second staf rotatably mounted in said base and plate, a plate attached to said second sta-if, gear teeth cut in one end of said plate and meshing with said pinion, a tubular membei` associated With said base, an. indicating rod non-rotatably and slidably mounted in said tubular member, a rack formed on said indicating rod, and gear teeth cut in the other end of said plate and meshing With the rack on the indicating rod.

2. An improved indicating device, comprising a gear, an indicating mechanism driven thereby, a circular rack meshing with said gear, means for preventing rotative movement of said rack, relative to said gear, and means permitting disengagement of said last named means whereby the rack may be rotated to present an unworn portionto the gear.

3. An improved indicating device, comprising a sliding bar, a key attached thereto near one end thereof, a holder, a keyway in said holder, said key fitting into said key- Way to prevent rotative movement of the sliding bar, a gear, and a circular rack cut on said sliding bar and meshing With said gear on a line extending longitudinally of the bar, said lzey being o1 such length that it may be slid temporarily ont of engagement with the lreyway, whereby the sliding bar may be rot-ated to present an unworn portion thereon to the gear and an indicating hand associated with and `operable through' the medium of the indicating rod.

ln testimony whereof, I have signed my name tol this specification.

JOSEPH A. GREEN. 

